1. Technical Field
Embodiments of the inventive subject matter described herein relate to controlling the speeds at which axles of a vehicle are rotated to propel the vehicle.
2. Discussion of Art
Some vehicles include powered axles that are rotated to propel the vehicles. To control the speeds at which the axles are rotated, the speed at which the vehicle is traveling is measured. For example, the axles may be rotated at speeds that are based on the measured speed of the vehicle to generate sufficient tractive effort to propel the vehicle.
Various approaches have been used to determine a speed of the vehicle. Radar systems have been used, but have been found to be unreliable and prone to mechanical failure when used with vehicles. Additionally, the radar systems have been found to have poor accuracy in measuring vehicle speeds at relatively low speeds. Wheel speed sensors have been used to measure the rotation speeds of wheels of the vehicle. But, exclusive use of these sensors may not be accurate due to slippage between the wheels and the track during motoring and/or braking. Another approach is referred to as a Sampled Axle Speed (SAS) algorithm. SAS involves decreasing the torque applied to one axle of a set of axles of the vehicle to eliminate or avoid slippage of the wheel along a track. The speed of this axle is sampled to acquire a potentially more accurate vehicle speed. This approach, however, decreases the tractive effort generated by the vehicle, and may not work well at higher acceleration rates and/or when a significantly heavy load is being hauled by the vehicle. It may be desirable to have a system and method that differs from those that are currently available.